Station stop control arrangement for self-propelled vehicles

ABSTRACT

Coils tuned to a first and a second frequency are positioned in pairs along the track in approach to the station at which trains are to stop automatically, two pairs being shown. -the first pair are spaced a distance which establishes a selected passage time in accordance with average train speeds while the second pair are separated a distance proportional to predetermined differences in train lengths. On the train two transmitter and/or receivers are coupled by a common pair of coils to inductively respond to the corresponding frequency wayside coil. Response to the initial first frequency coil opens a gate which enables the other transmitter-receiver for a predetermined time or distance interval to respond to the second frequency wayside coil of the initial pair. Only if the train coils pass this second frequency coil during this gating interval is the station stop program initiated by the response of the second transmitter-receiver. While passing the second set of wayside coils, the response of the first or second transmitter-receiver is selectively used, in accordance with a preset train length condition, to modify the station stop program to improve the accuracy of the station stop position.

llite tates Patent [191 [111 flfilfifi Grundy et al. ay 1, 1973 STATIONSTOP CONTROL 57 ABSTRACT ARRANGEMENT FOR SELF- PROPELLED VEHICLES COIIStuned to a first and a second frequency are posh tioned in pairs alongthe track in approach to the sta- InVeIltOrSI Reed G y Murrysville; tionat which trains are to stop automatically, two Donald Lime, Gl'eensburg,both pairs being shown. Othe first pair are spaced a distance of whichestablishes a selected passage time in ac {73] Assigneez WestinghouseBrake Company, cordance with average train speeds while the secondSwissvale, pair are separated a distance proportional to predetermineddifferences in train lengths. On the train two [22] Flled: 1971transmitter and/or receivers are coupled by a common [21] Appl 116,033pair of coils to inductively respond to the corresponding frequencywayside coil. Response to the initial first frequency coil opens a gatewhich enables the other [52] US. Cl. ..246/l82 B, 246/184transmittepreceiver for a predetermined time or [51] lift. Cl. ..B61l3/06 distance interval to respond to the Second frequency [58] Fleld ofSearch ..340/l64 R, 263; wayside Coil of the initial pain o if the trainCoils 246/182 184; 307/232; 328/109 110 pass this second frequency coilduring this gating interval is the station stop program initiated by the[56] References C'ted response of the second transmitter-receiver. WhileUNITED STATES PATENTS passing the second set of wayside coils, theresponse of the first or second transmitter-receiver is selectively Bused in accordance a preset train length condi- 3'355709 11/1967 340/164RX tion, to modify the station stop program to improve 3,555,512 1/1971Mustatn ..340/I64R Primary ExaminerGerald M. Forlenza AssistantExaminer-George H. Libman Att0rney-H. A. Williamson, A. C. Williamson,Jr. and

the accuracy of the station stop position.

9 Claims, 3 Drawing Figures Patented May 1, 1973 QUE 345 nan swag;

Reed f]. Grundy ma flonald H. LzZLe.

STATION STUIP CONTRUL ARRANGEMENT FOR SELF-PROPELLED VEHICLES Ourinvention relates to a station stop control arrangement forself-propelled vehicles. More specifically, the invention pertains to acontrol arrangement for triggering or initiating the operation ofautomatic station stop apparatus on self-propelled railroad trains orequivalent vehicles moving along a fixed right-ofway.

The procedure for controlling an automatic station stop by aself-propelled vehicle requires that certain information be transmittedfrom the wayside to the vehicle or train. This information includes suchitems as a command to initiate or trigger the station stop procedure,the distance yet to go to the station, and the direction in which thetrain is moving, that is, whether it is approaching a station ordeparting from a station. Several methods for transferring signals ofone type or another from the wayside to vehicles moving along aright-of-way are known and have been used in the art. Where control ofstation stopping procedures is involved, there are several specificrequirements for the wayside to vehicle signal transmission system.First, and probably foremost, the system must assure that the train doesnot respond to false signals from the wayside, that is, false triggers.Further, such action should not be initiated, even with valid signals,when a train moves along the right-of-way in a reverse direction pastthe location of the wayside trigger arrangement. Also, the arrangementmust allow data for different lengths of trains, that is, coupledvehicles, and for different stopping positions to be transmitted to thetrain. The

first listed requirement presents special problems due to the probablepresence of false triggering signals created by external causes. Suchfalse signals are particularly prevalent in electrified transportationsystems due to the interruptions and irregularities of the propulsioncurrents and to sparking between the wayside power source and the trainpickup devices. A necessary feature, then, of any automatic station stopsystem is that the triggering arrangement meet all of the listedrequirements to provide a reliable control system.

Accordingly, an object of our invention is an improved controlarrangement for an automatic station stopping system for vehicles movingalong a fixed rightof-way.

It is also an object of our invention to provide a station stop controlarrangement which eliminates the false triggering or initiation of thestopping procedure due to extraneous and/or false signals.

A further object of our invention is a station stop control arrangementwhich includes two or more successive trigger signal locations within apredetermined distance at the point at which the station stop proceduresare initiated.

Still another object of our invention is a station stop controlarrangement requiring the vehicle to pass two successive trigger deviceswithin a predetermined time or distance interval and in a preselectedorder to initiate the station stop program operation.

it is also an object of our invention to provide a station stop controlarrangement for vehicles which includes a first pair of spaced anddistinct trigger devices which cooperate with vehicle-carried apparatusto initiate the station stop program and similar trigger devices locatedalong the approach track within the original distance in order toactuate a modification of the station stop control in accordance withthe train performance during the stopping program.

Yet another object of the invention is a station stop controlarrangement in which the vehicle-carried apparatus must respond in apreselected order and within a preset gating interval to two distinctand successive triggering devices located along the right-of-way inorder to initiate the station stop program for the vehicle.

A still further object of the invention is a station stop controlarrangement in which the train-carried apparatus initiates the stationstop program only in response to successive and distinct signalsreceived from wayside devices within a preset time interval and whichmodifies the program progression to increase the accuracy of the stop inresponse to a second reception of one or another of similar signalsselected in accordance with the train length.

Other objects, features, and advantages of the invention will becomeevident from the following specification when taken in connection withthe accompanying drawings and appended claims.

In the practice of our invention, pairs of wayside devices, each one ofa pair having a distinctive characteristic different from the other, arepositioned along the vehicular right-of-way, each location being apreselected distance in approach to the station at which stops are made.Each vehicle, normally a coupled train set, carries apparatus whichresponds in a distinctive manner during passage by each wayside devicein accord with the particular characteristic of that device. Normallyeach train has two sets of apparatus, each responding only to waysidedevices having a particular one of the two distinctive characteristics.Each train apparatus unit produces an output signal whenever the trainpasses the corresponding device if preselected conditions are met. Inthe specific showing herein, the wayside devices are coils tuned to oneor the other of two distinct frequency characteristics. The coils ofeach frequency characteristic are alternately located along the stretchof right-of-way. Each set of train-carried apparatus includes a tunedtransmitter-receiver unit which responds to passage by the wayside coilhaving the same frequency characteristic to produce an output signal,unless the train-carried apparatus is otherwise inhibited from suchoperation.

Gating means are interposed in the train-carried apparatus to normallyinhibit the second frequency set from responding to the correspondingwayside coils. The response of the first frequency set of trainapparatus upon passage of the corresponding wayside coil opens thisgating means for a predetermined interval, established by time ordistance measurements. If the second frequency wayside coil is passedduring this interval, an output signal is produced by the correspondingtrain-carried apparatus. This second output signal is applied to triggeror initiate the station stop program, that is, it activates the stationstop control apparatus on that particular train.

The station stop apparatus is programmed to stop the vehicle or train atthe next station in advance in accordance with a preset decelerationprogram and a preselected stopping point. To increase the accuracy ofthe station stops in accordance with predetermined desired stoppingconditions, and especially where different length trains are used, atleast one additional set of wayside coils is provided in the approachbetween the initial set and the actual station location. The second setis spaced apart in accordance with predetermined conditions of trainlengths. The train apparatus is also provided with a selectorarrangement to establish the train length character effective for thatparticular train, specifically shown as being a first or second trainlength condition. The response of the first or second frequencyapparatus on the train is then used, that is, the output signal isapplied in accordance with the train length selection, to modify thestopping program in accordance with the train deceleration performanceto that point.

We will now describe in greater detail an arrangement embodying thefeatures of our invention and then shall point out the novelty thereofin the appended claims, referring in the description to the accompanyingdrawings in which:

FIG. 1 is a schematic view of a stretch of right-of-way in the approachto a station with wayside devices for a station stop system involvingthe features of our invention.

FIG. 2 is a diagrammatic illustration of vehicle-carried apparatus whichcooperates with the wayside apparatus shown in FIG. 1 to provide thestation stop control arrangement embodying our invention.

FIG. 3 is a diagrammatic illustration of the location of a portion ofthe vehicle-carried apparatus of FIG. 2 as used for a particular type ofvariable train length operation. I

In each of the figures of the drawings, similar reference charactersrefer to similar parts of the apparatus.

Referring now to FIG. 1, a stretch of right-of-way T, over which moveself-propelled vehicles, is shown by conventional single linerepresentation. The dash line block V at the left designates such avehicle which normally moves from left to right along the right-of-wayT. An obvious specific example of such systems are rapid transit carsmoving along a railroad track. It is to be expected, of course, that aplurality of vehicles V, or rapid transit cars in the example, will becoupled into train sets for actual operation and the symbol V alsorepresents such trains. Such stretches of right-of-way T may be alsoused for reverse movements of the vehicles or trains, either underselected conditions or as a normal type of operation. Shown along theright-of-way at the right is a station platform, illustrated byconventional block, at which the vehicles or trains are expected tostop. For purposes of a specific description, it is assumed that thepreset or desired operation requires that the center of the stoppedtrain be spotted substantially at the center of the station platform. Ofcourse, other degrees of stopping accuracy or conditions may be used.

Located along the approach to the station platform are pairs of waysidedevices to mark the approach stretch and control the automatic stationstop operation of approaching trains. The first set passed by anapproaching train triggers or initiates the station stopping program andthe sets closer to the station then actuate a modification of theprogram in order to increase or improve the accuracy of the stop. Inthis specific showing, each wayside device is a single coil having aselected number of turns and tuned by a capacitor to a preselectedfrequency characteristic. In other embodiments, each wayside device maybe a transmitter tuned to provide a signal with a selected frequencycharacteristic for reception by the train-carried apparatus, as will bediscussed shortly. ONly two pairs of coils are shown in the actualillustration as this is sufficient to illustrate our invention. Thefirst set, that is, the trigger or initiating set, comprises the waysidecoils WCl and WC2 while the second set which actuates the modificationof the station stopping program comprises the wayside coils WCIA andWC2A. Coils WCl and WCIA are tuned by identical capacitors C1 to a firstpreselected frequency F1 while the other two coils are each tuned byidentical capacitors C2 to the second selected frequency F2. It is to benoted that additional sets of such wayside devices, or more than a pairin each set, may be used if an increased stopping accuracy is desired orif necessary because of the number of different train lengths normallyoperated, but the two pairs illustrated are sufficient to describe thefeatures of our invention.

A more specific example of the apparatus involved will be describedshortly in connection with FIG. 2'. However, it should be noted that thefirst pair of wayside coils are spaced a predetermined distance d fromeach other while the second set are spaced apart a predetermineddistance y which is selected in accordance with the various trainlengths used and will normally be different than the distance d. The twoshorter distances x illustrated as extending each side of coil WCZ willbe defined and described shortly. It is obvious that a vehicle V movingalong the right-of-way from left to right passes the coils in successionas it approaches the station. In other words, the vehicle or trainalternately passes coils tuned to frequencies FL and F2.

Referring now to FIG. 2, the particular portion of the right-of-way Tfrom FIG. 1 is illustrated which includes the location of the initialset of wayside coils WCI and WC2. The vehicle V, which for example maybe a train of coupled vehicles, is shown approaching along theright-of-way or track by the dash line block. The remainder of theapparatus illustrated in FIG. 2 is mounted on the illustrated vehicle Valthough not all shown specifically within the confines of the blockrepresentation of the vehicle. Of particular note are the twotrain-carried coils TC and RC which are mounted to pass in relativelyclose inductive relationship with wayside coils WCl and WCZ and withother sets of wayside coils involved in the control arrangement. Thespecific mounting locations of the various coils illustrated isunimportant to the details of our invention, the only requirement beingthat the mounting be such that the train or vehicle-carried coils passin an inductive relationship with the wayside coils. In a specificexample, the wayside coils WC may be mounted between the rails of theright-of-way while the train-carried coils TC I and RC are mounted onthe bottom of the vehicle or car of the train.

As the specification progresses, it will become apparent to thoseskilled in the art that several types of apparatus are usable in orderto provide the control signals for the station stop program arrangementherein described. However, for purposes of this description, thespecific type of apparatus which is assumed is similar to that disclosedin Letters Patent of the United States No. 2,828,480, issued to L. R.Golladay on Mar. 25, 1958, for Train identification Systems. Anotherexample of the same type of apparatus is illustrated in Letters Patentof the United States No. 2,753,550, issued to R. W. Treharne on July 3,1956, for Vehicle Reporting Systems. In adapting the patented apparatusas a specific example herein, the wayside apparatus as specificallyillustrated in the Treharne patent is used on the vehicle V and thetuned vehicle coils shown in the Treharne arrangement are moved to thewayside as coils WCl, WC2, etc. The specific references for thetrain-carried coils TC and RC herein are taken from the Treharne patentand designate the transmitter and the receiver coils, respectively,associated with the transmitter-receiver. These coils are, of course,also similar to the coils L1 and L2 of the Golladay arrangement. Thecoils WC herein illustrated along the wayside of the right-of-way aresimilar to the coils VC in the Treharne system and coil L3 in theGolladay system. Here each wayside coil is tuned to a single presetfrequency only and no selection is provided.

The vehicle apparatus is shown by conventional blocks since all elementscomprise known apparatus and any one of several types may be used. Atransmitter-receiver unit for each frequency is shown by the two blocksdesignated as the F1 and F2 transmitterreceiver units. Reference hasalready been made to the Golladay and Treharne patents for specificexamples of such apparatus. In the present state of the art, these unitsare preferably designed to include solid state circuitry, but suchredesign is not involved in the specific features of our invention. Thetransmitter-receiver units are connected in multiple to the single setof traincarried coils TC and RC. A gating means or circuit arrangement,

conventionally shown by the block' designated Gate 1, is interposed inthe connections from coil RC to the F2 transmitter-receiver. Any knowntype of gating circuit having a set or open gate input and a reset orclosed gate input may be used. A similar gating means represented by theblock designated Gate 2 is connected into one of the leads from theoutput of the F1 transmitter-receiver. If desired, Gate 1 may bealternately connected in the output lead from the F2transmitter-receiver, as will become apparent fromthe subsequentdescription.

it will be understood that, if the wayside devices are transmittersproviding distinctive signals for pickup by the train apparatus,receiver units only are used tuned to respond to the frequency signalsfrom the wayside and the train coils are connected to receive thesignals in proper form. The train apparatus may include a separatereceiver unit tuned to each frequency or a single unit broadly tuned torespond to all frequency signals from the wayside. In either case, adistinctive output signal is produced on the train when each waysidedevice is passed by the train pickup coils. Such modifications of theillustrated apparatus will be apparent to those skilled in the art andsuch embodiments are included as part of our disclosure.

The inputs to the two control connections of Gate 1 at times come froman interval measurement unit illustrated by the conventional block, sodesignated, shown below the F11 transmitter-receiver. Various types ofknown apparatus can be used for this purpose, the only requirement beingthat, during a preset. interval measured following a single input pulse,two successive output signals are provided. This establishes a presetinterval of time subsequent to the input to this interval measurementunit received from the Fl transmitterreceiver when the train passes awayside coil WCll. As mentioned, these first and second signals from theinterval unit are applied to the set and reset inputs, respectively, ofGate 1. This interval of time during which Gate 1 is thus opened to passsignals from coil RC is represented by the successive gating distance xshown on each side of coil WC2 in FIG. 1. One type of apparatus whichmay be used to measure this interval is a timing unit, such as amonostable multivibrator or a bank of counters. Such a timer unitproduces the two gating pulses in accordance with the known average 1speed of the various vehicles V so that each vehicle is normallyoccupying a point within the range 1 x during the gating interval inorder to allow the F2 transmitter-receiver to respond during theinductive relationship of coils TC and RC with wayside coil WC2.Alternately, this interval measurement unit may be a distance measuringdevice, for example, a counter and wheel tachometer, which producesgating pulses when the vehicle has traveled two preset distances afterthe unit is activated by the signal from the F1 transmitterreceiver.These distance pulses occur and activate Gate 1 only while the train iswithin the selected gating distance range, i.e., the preset distance xon each side of coil WC2.

As is more fully explained in the previously mentioned referencepatents, when the vehicle coils TC and RC pass in inductive relationshipto a wayside coil WC, the correspondingly v tuned transmitter-receiverunit produces an output signal. For example, when vehicle V passes coilWCll, the F1 transmitter-receiver produces an output at the circuitconnection shown at the bottom of the conventional block. Forgetting forthe moment the effects of Gate l, a corresponding output signal isprovided by the F2 transmitter-receiver when the vehicle passes waysidecoil WC2. These out put signals from the transmitter-receivers areapplied, in various manners to be discussed shortly, to a Station StopProgram Controls unit SSP. This apparatus is shown by a conventionalblock since various types of stop program control apparatus are known inthe vehicle control art. For example, the apparatus may be adapted fromthat shown in Letters Patent of the United States No. 3,188,463, issuedto C. M. Hines on June 8, 1965, for Brake Control Apparatus for UnmannedTrains. The requirement herein is that, with a proper input signal tounit SSP at the upper input connection designated initiate program, thepredetermined station stop program is initiated to control thepropulsion means of vehicle V to stop the vehicle or train at a stationa known distance in advance. A second and later input at the SSPconnection designated as modify program, occurring at a known lesserdistance to the station, modifies the station stop program, inaccordance with the performance of the train between the programinitiating and modifying points along the stretch, to improve theaccuracy of the actual station stop in fulfilling the preselectedposition requirements. The patent system cited above may be adapted tothis operation by controlling either or both of the relays 22 and 23 tooperate when the train passes the subsequent program modification pointsalong the right-of-way, rather than the illustrated control by theinternal slow release characteristics of each relay. This allows thestation stop program to be modified on a space or distance basis ratherthan a straight time basis. If only a single modification location isused, the patented system would incorporate only a single relay such as22. Obviously other types of stop program apparatus may be adapted foruse with our invention.

The final item of apparatus carried on the vehicle is a train lengthselector means TLPB, shown as being a push-pull stick type push buttondevice, but any twoposition circuit selector is of course usable forthis purpose. As illustrated, circuits are normally completed throughcontacts 1A and 1B of the push-pull device TLPB to select a firstpredetermined condition of train length. In the other position of thedevice, circuits are completed through contacts 2A and 28 to establish asecond length condition. As illustrated by the conventional symbol used,the push-pull device remains in the position to which it was lastactuated until it is returned to the other position by a reverseprocedure. This length selection is provided to increase the accuracy ofthe assumed center train, center platform station stop requirement andis correlated with the selected distance y between the second set ofwayside coils WClA and WC2A illustrated in FIG. 1.

We shall now describe the operation of the embodiment of the inventionillustrated in FIGS. 1 and 2 for a multi-unit train, that is, aplurality of vehicles coupled together into a train set. In designing aspecific installation of this embodiment, certain operating conditionsmust be established or at least assumed. In the following description,the first such assumption is that nearly all of the trains operatingalong the illustrated right-ofway have one or the other of twopredetermined lengths, that is, include a predetermined number ofvehicles coupled together. It is also a condition that the train coilsTC and RC at the front of the train, that is, located on the lead car,are the only ones active on these trains to control the apparatus. Aspreviously mentioned, the requirement may be preset that the train is tostop with its center at the center of the station platform, although thedescription will make it obvious that any point of stopping may bepreselected.

Referring first to FIG. 1, coils WC]. and WC2 are located at apredetermined distance in the approach to the illustrated station inaccordance with the preset stopping control program. The distance d atwhich these coils are spaced is established in accordance with theaverage train speed at this location and the characteristics of theinterval measuring device used on the train. This will result in Gate 1being opened, as controlled by F1 transmitter-receiver, at the timeduring which the train coils are within the distance range x x on eitherside of coil WC2. The second set of coils WClA and WC2A are located asrequired by the stopping program to allow sufficient remaining distanceto modify the stopping procedure in accordance with preceding trainperformance. The distance y is fixed proportional to the differencebetween-the two train lengths which nearly all of the trains will have.For example, the distance y may be equal to one half of the differencebetween the two principal train lengths used in this system.

Referring now more specifically to FIG. 2, we assume that the trainlength involved is a first condition so that push button TLPB remains inthe position illustrated. The positioning of this device TLPB to selectbetween the two train length conditions is accomplished, in accordancewith the known length, by the attendant who is assigned to ride on thetrain, or by the crew at the yard where the train was made up prior toits dispatch along the right-of-way. For the present assumption, if pushbutton TLPB had not been in its first position, it would be so placed bypulling the operating arm. When the train or vehicle V passes waysidecoil WCl, the train coils TC and RC are placed in inductive relationshipto the wayside coil and the F1 transmitterreceiver unit produces anoutput signal, as explained in detail in the previously mentionedpatents of Golladay and Treharne. This output signal appears on the leadat the bottom of the F1 block and is applied to the interval device.Since Gate 2 is presently closed, that is, in its circuit interruptingcondition, there is no passage of this signal along the multiple paththrough Gate 2. Actuated by this signal, the interval unit operates tosupply the successive signals from its output leads in accordance withthe characteristics preselected. The initial signal is applied to theset input for Gate 1 and the second signal, at a predetermined timeinterval later, to the reset input circuit. The application of thisreset pulse to the corresponding input of Gate 2 is immaterial at thispoint in system operation. Gate 1 is thus opened, that is, in itscircuit completed condition, for this time interval during which thetrain coils should be within the distance range x x of FIG. 1.

If train V passes coil WC2 during this gate open period, coils TC andRC, being in an inductive relationship with coil WC2, actuate the F2transmitter-receiver to respond to the tuned wayside coil to produce anoutput signal at the connection at the right side of the conventionalblock. This output signal from the unit F2 is applied to the initiateinput lead of the Station Stop Program Controls apparatus SSP. Unit SSPthen controls the propulsion and/or braking apparatus of the train in apredetermined manner to stop the train at the station with, as will beexplained, a later modification which may be required to improve theaccuracy. It should be noted that whether or not contact 2A of deviceTLPB is closed, this initial first output from the F2transmitter-receiver unit is only effective on the initiate" input leaddue to the internal operation of unit SSP.

If transmitter-receiver F1 is actuated by a false signal, due to someexternal cause, at some other location along the right-of-way, train Vwill not be passing wayside coil WC2 during the gating interval producedby the interval unit. Since there will be no wayside coil WC2 toinductively react with the train-carried coils, the F2transmitter-receiver is not actuated and there is no trigger pulse toinitiate the station stopping program of the train. If the coils TC andRC are actuated at some other location in any manner by an externalcause to produce a false F2 signal or relationship, the closed conditionof Gate 1 prevents the false actuation of the 9 F2 transmitter-receiverand no initiate program signal is incorrectly applied to unit SSP. It isalso improbable that successive false signals simulating frequencies Flland F2 from wayside coils WC and WC2 will be induced in coils TC and RCwithin a proper time or distance interval to cause Gate II to be openwhen the false F2 signal occurs so that the F2 transmitter-receiver willbe incorrectly actuated. It will also be obvious that, if the train ismovingin the opposite direction along the right-of-way so that it passeswayside coil WC2 prior to its passage of coil WCl, Gate 1 is not openwhen the train passes coil WC2 and the F2 transmitter-receiver unittherefore cannot respond to the inductive relationship between the traincoils and the wayside coil. Thus the arrangement has a directionselection automatically built into the operation and the station stop isnot initiated unless the train is moving in the direction toward thestation area. Said in another way, the train must be moving in theproper direction and pass a set of wayside coils WCl and WC2 within aproper time interval, producing both output signals, in order toinitiate the station stopping program. Under no other conditions willthe program be initiated.

We return now to a train which has properly operated the twotransmitter-receiver units within the correct time interval so that thestation stop program has been initiated. When this train passes coilWClA, I

the same output is produced by the F1 transmitterreceiver as when theinitial wayside coil was passed. The interval measurement is againactuated, providing during the preset interval the set and reset signalsto Gate 1, but at this time these are immaterial to the systemoperation. The F1 unit output signal is also applied to Gate 2 which,under the influence of the set signal received from the station stopprogram apparatus SSP, is in its open or circuit completed condition. Asindicated by the legend, this signal is provided by unit SSP whenever aprogram is active to stop the train and the circuit is completed overcontact 1B of push button TLPB to the set input of Gate 2. The signalfrom the F1 unit is thus applied through Gate 2 and over contact 1A ofdevice TLPB to the modify program input of unit SSP. It willbe notedthat Gate 2 is held in its open condition by the set signal from unitSSP even though the brief reset signal from the interval unit associatedwith the F1 transmitter-receiver is applied to the reset input of Gate2. The modify signal input to unit 88? causes the active stationstopping program to be modified, in accordance with the trainperformance to that point, to increase the accuracy of the specific stopat the station platform. It will be further noted that Gate 1 is openfor the same time interval as when the train was passing coils WCI andWC2. Gate l is not under these conditions affected by the programactive"signal from unit 88? since contact 28 of push button TLPB is open. TheF2 transmitter-receiver may or may not be actuated by the passage of thetrain by coil WC2A depending upon whether the predetermined distance yrelatively corresponds to the distance d. However, the operation of theF2 transmitterreceiver at this time is immaterial since any possibleoutput would be ineffective, i.e., blocked from. reception by unit SSPby open contact 2A of selector TLPB. Thus the station stopping programfor this particular train was initiated as the train passed coils WClland WC2 within the predetermined gating interval and was later modifiedin accordance with the preset train length condition as the train passedthe location of coils WCIA and WC2A, resulting in a stop by the train atthe center of the station platform.

If the train in question has a second condition length so that deviceTLPB is set in its position 2, there is no change in the previouslydescribed action as this train V passes the location of coils WCl andWC2. The eventual output from the F2 transmitter-receiver is applied tothe initiate" input of unit SSP and the stop program is triggered andproceeds. When the train passes coil WCIA, the F1 transmitter-receiverresponds as before and the interval measurement unit produces its gatingsignals. The output signal from the transmitter-receiver F1 is blockedat Gate 2, however, since this gate has not been set to its openposition because contact 18 of length selector TLPB is open to interruptthe program-active signal application. However, the program-activesignal is applied over contact 28 of device TLPB to the set input onGate 1 to hold this gate in its open or circuit completed conditionthroughout this stopping period. Thus, when train coils TC and RC passwayside coil WC2A, the F2 transmitter-receiver is actuated since Gate 1is open and an output signal is produced. This output signal is applied'over contact 2A of device TLPB to the modify input of unit SSP. Thusthe station stop program is not modified until the train reaches thelocation of the second coil of the second set, that is, coil WC2A. Thisis proper since the second condition is a longer train length andrequires that the modification occur at a later time in order for thedesired stop position to result. Regardless of any reset signals whichmay be applied to the two gates during the passage of the train alongthe right-of-way, each gate is positively reset to its blocked or closedcondition by the reset signals from unit 58? when the vehicle hasactually stopped at the station.

If more than two lengths of trains are normally used in the system, thearrangement of train coils such as illustrated in FIG. 3 may be usedwith the remainder of the train-carried apparatus of FIG. 2 to assurethat the modifying signal for the station stop program is applied at theproper time. Each line of FIG. 3 represents a different length train,with the assumption that a train is made up from married pairs of cars.This term married pairs designates a semi-permanently coupled pair ofcars, as shown in the top line of FIG. 3, which has only one completeset of operating apparatus, including this station stop controlarrangement. During the makeup of a train of this type, the set of traincoils TC and RC nearest the center of the assembled train is madeactive, that is, made to be the controlling set of train-carried coils.It is this active set of coils TC and RC which is illustrated in thevarious train combinations of FIG. 3. The conditioning of a set of traincoils into the active state to control the train stopping programs isaccomplished by the crews at the yard where the trains are made up. Asindicated in FIG. 3, if an odd number of married pairs of cars is used,the active train-carried coils are separated by one car length from thephysical center of the resulting train combination. If an even number ofmarried car pairs is used, as shown in the second line of FIG. 3, theactive train coils are physically located at the train center. Inaddition to making a set of the coils active, if an odd number ofmarried car pairs is used, the length selector push button TLPB at thecontrolling location of the station stop apparatus is set to trainlength condition 2, that is, contacts 2A and 2B are closed by pushingthe device. If an even number of married car pairs is used, the deviceTLPB at the control location is set to condition 1.

In connection with this arrangement, the wayside distance y shown inFIG. 1 between the second set of wayside coils is fixed at the length ofa single car, not a married pair but a single car. The operation of thetrain-carried apparatus, as described previously, depends upon theposition of push button TLPB. When the train includes an even number ofmarried pairs, as illustrated by the middle line of FIG. 3, themodifying control on unit SSP is applied when the active TC, RC coilspass wayside coil WClA. Since these train coils are at the center of thetrain, this is proper to obtain a center of the station platform trainstop. If the train is composed of an odd number of car pairs, such as inthe top and bottom lines of FIG. 3, the modifying control occurs whenthe train coils pass wayside coil WC2A. The middle of that train is thenopposite coil WClA so that the same stopping distance to the station isin effect for the center of the train. It will be obvious from theimmediately preceding description that, if married pairs of cars are notused but individual cars are assembled into various length trains, asimilar arrangement of making active a particular set of train-carriedcoils TC and RC will result in the same type of operation.

The arrangement of our invention thus provides a station stop programcontrol which assures that action is initiated only when valid signalsare received on the train from the wayside devices. The arrangementfurther provides for modifying the stop program process to improve theaccuracy of the final stop at the station in accord with the trainperformance over a selected length of the track and in accordance with apreselected train length condition. In this manner, the stoppingaccuracy of different length trains operating over the same right-of-waycan be held within the same minimum distances. The desired result isobtained by using conventional apparatus arranged in accordance with thefeatures of the invention and operating as described herein. Thearrangement is reliable and eliminates both false operation fromimproper wayside signals and the initiation of the stop control ontrains operating in the reverse direction along the right-ofway. Animproved, desirable, and accurate type of station stopping control isthus achieved.

Although we have herein shown and described but one complete arrangementof a station stop control arrangement for self-propelled vehicles, it isto be understood that various changes and modifications within the scopeof the appended claims may be made without departing from the spirit andscope of our invention.

Having thus described our invention, what we claim a. an initial set offirst and second wayside means positioned in spaced relationship alongsaid rightof-way at a preselected location in approach to each station,each means of a set having a distinctive characteristic,

b. at least one other set of said first and second wayside meanspositioned in spaced relationship along said right-of-way at anotherselected location closer in approach to each station,

c. first and second signal means on said vehicle, each uniquelyresponsive to passage by a first and second wayside means, respectively,for producing an output signal,

(I. a station stop program control means on said vehicle control by saidsecond signal means and operable when initially activated by an outputsignal from that signal means for controlling the vehicle propulsion andbraking apparatus to stop the vehicle at the next station in advancealong said rightof-way,

e. a first gating means on said vehicle connected to normally inhibitresponse by said second signal means to a second wayside means,

f. an interval measurement means on said vehicle controlled by saidfirst signal means for establishing a predetermined interval subsequentto said first signal means output signal,

g. said interval measurement means connected for activating said firstgating means only during said predetermined interval to permit saidsecond signal means to respond to a second wayside means,

h. said station stop program control means further controlledselectively in accordance with a preset vehicle length condition by saidfirst or second signal means during response to each other set ofwayside means for modifying the established train stop program inaccordance with vehicle propulsion conditions existing when thatadditional set is passed by said vehicle, and

i. a second gating means controlled by said program control means andconnected for inhibiting control of said program control means by saidfirst signal means except when a station stop program has beenpreviously activated.

2. A control arrangement as defined in claim I, in which said intervalmeasurement means is a timing device which establishes saidpredetermined interval beginning a timed delay period after said firstsignal means output signal preselected in accordance jointly with theaverage speed of vehicles at and the spacing between said initial set ofwayside means so that each vehicle passes the initial second waysidemeans during said predetermined interval.

3. A control arrangement as defined in claim 1, in which said intervalmeasurement means is a distance measurement device jointly responsive toa first signal means output signal and the movement of that vehiclealong said right-of-way to establish said predetermined interval whenthat vehicle has moved a preselected distance, at which the initial setof wayside means is spaced apart, beyond the location of a first waysidemeans so that said vehicle passes the second wayside means of saidinitial set during said predetermined interval.

4. A control arrangement as defined in claim 1 for a plurality of saidvehicles operating along said right-ofway coupled into a train havingone or the other of two predetermined train length conditions and onlyone active set of said first and second signal means, the combinationfurther including,

a. a train length selector means on said train associated with saidactive set of signal means and selectively operable to a first and asecond position in accordance with a first or second length condition ofsaid train,

. a circuit network connected between said program control means andboth said gating means and controlled by said length selector means foractivating said second or said first gating means in accordance as saidlength selector means is operated to its first or second position,respectively, when said program control means has been previouslyactivated,

c. another circuit network also controlled by said length selector meansand connected for supplying to said program control means, when saidtrain passes an additional set of wayside means, the output signalproduced by said first or second signal means in accordance as saidlength selector means is operated to its first or second position,respectively,

. said second gating means interposed in said other circuit network forinhibiting the supply of the output signal from said first signal meansto said program control means except when said program control means isalready activated.

5. A control arrangement as defined in claim 1, for a plurality of saidvehicles coupled into a train having one or the other of twopredetermined train length conditions and only one active set of saidfirst and second signal means, which further includes,

a train length selector selectively operable to a first and a secondposition as the corresponding train has a first or a second lengthcondition, respectively,

b. a first circuit including a first position contact of said lengthselector and said second gating means and connected for at timessupplying the output signal of said first signal means to said programcontrol means to modify the stopping program when the train passes anadditional set of wayside means,

c. a second circuit including a second position contact of said lengthselector and connected for at times supplying the output signal of saidsecond signal means to said program control means to modify the stoppingprogram when the train passes an additional set of wayside means,

. a third circuit including another first position contact of saidlength selector and connected for supplying at times from said programcontrol means only while activated an activating signal to said saidfirst gatingmeans, v f. a reset circui connected to said first and saidsecond gating means from said program control means for supplying whenthe train has stopped a reset signal to deactivate any previouslyactivated gating means.

6. A control arrangement as defined in claim 4 in which,

a. said initial set of first and second wayside means is spaced apart afirst distance preselected in accordance with the time of occurrence ofsaid predetermined interval, so that said train will pass said secondwayside means of that initial set during said predetermined interval,

b. each additional set of first and second wayside means is spaced aparta second distance proportional to the difference in the length of trainshaving first and second length conditions.

7. A control arrangement as defined in claim 6, in which said intervalmeasurement means is a timing device which establishes saidpredetermined interval beginning a timed delay period, after an outputsignal from said first signal means, preselected in accordance with theaverage speed of trains at and the spacing between the initial set offirst and second wayside means so that each train passes the initialsecond wayside means during said predetermined interval.

8. A control arrangement as defined in claim 6, in which said intervalmeasurement means is a distance measurement device jointly responsive toan output signal from said first signal means and the movement of thattrain along said right-of-way to establish said predetermined intervalwhen that train has moved a preselected distance, at which the initialset of wayside means is spaced apart, beyond the location of a firstwayside means so that said train passes the second wayside means of saidinitial set during said predetermined interval.

9. A control arrangement as defined in claim 6 in which,

a. each first and second wayside means comprises a coil tuned to a firstor a second distinctive frequency characteristic, respectively,

. each first and second signal means is a transmitterreceiver pretunedto respond only at said first or second frequency characteristic,respectively,

c. each set of said first and second transmitterreceivers is coupledduring movement of that train along said right-of-way to each successivewayside coil, a particular transmitter-receiver responding to produce anoutput signal only when the coupled wayside coil is tuned to thecorresponding frequency characteristic.

1. A station stop control arrangement for a vehicle having propulsionand braking apparatus and movIng on a fixed right-ofway along which arelocated stations at which said vehicle is to stop, comprising incombination, a. an initial set of first and second wayside meanspositioned in spaced relationship along said right-of-way at apreselected location in approach to each station, each means of a sethaving a distinctive characteristic, b. at least one other set of saidfirst and second wayside means positioned in spaced relationship alongsaid right-of-way at another selected location closer in approach toeach station, c. first and second signal means on said vehicle, eachuniquely responsive to passage by a first and second wayside means,respectively, for producing an output signal, d. a station stop programcontrol means on said vehicle control by said second signal means andoperable when initially activated by an output signal from that signalmeans for controlling the vehicle propulsion and braking apparatus tostop the vehicle at the next station in advance along said right-of-way,e. a first gating means on said vehicle connected to normally inhibitresponse by said second signal means to a second wayside means, f. aninterval measurement means on said vehicle controlled by said firstsignal means for establishing a predetermined interval subsequent tosaid first signal means output signal, g. said interval measurementmeans connected for activating said first gating means only during saidpredetermined interval to permit said second signal means to respond toa second wayside means, h. said station stop program control meansfurther controlled selectively in accordance with a preset vehiclelength condition by said first or second signal means during response toeach other set of wayside means for modifying the established train stopprogram in accordance with vehicle propulsion conditions existing whenthat additional set is passed by said vehicle, and i. a second gatingmeans controlled by said program control means and connected forinhibiting control of said program control means by said first signalmeans except when a station stop program has been previously activated.2. A control arrangement as defined in claim 1, in which said intervalmeasurement means is a timing device which establishes saidpredetermined interval beginning a timed delay period after said firstsignal means output signal preselected in accordance jointly with theaverage speed of vehicles at and the spacing between said initial set ofwayside means so that each vehicle passes the initial second waysidemeans during said predetermined interval.
 3. A control arrangement asdefined in claim 1, in which said interval measurement means is adistance measurement device jointly responsive to a first signal meansoutput signal and the movement of that vehicle along said right-of-wayto establish said predetermined interval when that vehicle has moved apreselected distance, at which the initial set of wayside means isspaced apart, beyond the location of a first wayside means so that saidvehicle passes the second wayside means of said initial set during saidpredetermined interval.
 4. A control arrangement as defined in claim 1for a plurality of said vehicles operating along said right-of-waycoupled into a train having one or the other of two predetermined trainlength conditions and only one active set of said first and secondsignal means, the combination further including, a. a train lengthselector means on said train associated with said active set of signalmeans and selectively operable to a first and a second position inaccordance with a first or second length condition of said train, b. acircuit network connected between said program control means and bothsaid gating means and controlled by said length selector means foractivating said second or said first gating means in accordance as saidlength selector means is operated to its first or second position,respectively, when said program control means has been previouslyactivated, c. another circuit network also controlled by said lengthselector means and connected for supplying to said program controlmeans, when said train passes an additional set of wayside means, theoutput signal produced by said first or second signal means inaccordance as said length selector means is operated to its first orsecond position, respectively, d. said second gating means interposed insaid other circuit network for inhibiting the supply of the outputsignal from said first signal means to said program control means exceptwhen said program control means is already activated.
 5. A controlarrangement as defined in claim 1, for a plurality of said vehiclescoupled into a train having one or the other of two predetermined trainlength conditions and only one active set of said first and secondsignal means, which further includes, a train length selectorselectively operable to a first and a second position as thecorresponding train has a first or a second length condition,respectively, b. a first circuit including a first position contact ofsaid length selector and said second gating means and connected for attimes supplying the output signal of said first signal means to saidprogram control means to modify the stopping program when the trainpasses an additional set of wayside means, c. a second circuit includinga second position contact of said length selector and connected for attimes supplying the output signal of said second signal means to saidprogram control means to modify the stopping program when the trainpasses an additional set of wayside means, d. a third circuit includinganother first position contact of said length selector and connected forsupplying at times from said program control means only while activatedan activating signal to said second gating means, e. a fourth circuitincluding another second position contact of said length selector andconnected for supplying at times from said program control means onlywhile activated an activating signal to said first gating means, f. areset circuit connected to said first and said second gating means fromsaid program control means for supplying when the train has stopped areset signal to deactivate any previously activated gating means.
 6. Acontrol arrangement as defined in claim 4 in which, a. said initial setof first and second wayside means is spaced apart a first distancepreselected in accordance with the time of occurrence of saidpredetermined interval, so that said train will pass said second waysidemeans of that initial set during said predetermined interval, b. eachadditional set of first and second wayside means is spaced apart asecond distance proportional to the difference in the length of trainshaving first and second length conditions.
 7. A control arrangement asdefined in claim 6, in which said interval measurement means is a timingdevice which establishes said predetermined interval beginning a timeddelay period, after an output signal from said first signal means,preselected in accordance with the average speed of trains at and thespacing between the initial set of first and second wayside means sothat each train passes the initial second wayside means during saidpredetermined interval.
 8. A control arrangement as defined in claim 6,in which said interval measurement means is a distance measurementdevice jointly responsive to an output signal from said first signalmeans and the movement of that train along said right-of-way toestablish said predetermined interval when that train has moved apreselected distance, at which the initial set of wayside means isspaced apart, beyond the location of a first wayside means so that saidtrain passes the second wayside means of said initial set during saidpredetermined interval.
 9. A control arrangement as defined in claim 6in which, a. each first and second wayside means comprises a coil tunedto a first or a second diStinctive frequency characteristic,respectively, b. each first and second signal means is atransmitter-receiver pretuned to respond only at said first or secondfrequency characteristic, respectively, c. each set of said first andsecond transmitter-receivers is coupled during movement of that trainalong said right-of-way to each successive wayside coil, a particulartransmitter-receiver responding to produce an output signal only whenthe coupled wayside coil is tuned to the corresponding frequencycharacteristic.